A recent trend is to use one or more fiber optic ribbons disposed in a tubular jacket to form a fiber optic cable. When such a cable is bent, which is usually the case when the cable is put to use in its intended environment, the ribbons within the cable also bend. When the plane of bend is the same plane delimited by the width of the ribbon, at least over a short distance, the optical fibers (usually made of glass) experience the most severe strain that can arise out of bending the ribbon. This strain can be mathematically expressed in relative terms as R.sub.1 /R.sub.2 where R.sub.1 is the distance from the center of either one of the terminal fibers to the center of the ribbon itself and R.sub.2 is the radius of curvature of the center line of the ribbon itself. See FIG. 5.
Lower strains are more desirable than higher strains for obvious reasons, e.g., fiber breakage and strain-induced attenuation. The fewer the number of fibers in a given ribbon, the smaller the ribbon width and thus the smaller value of R.sub.1 and the smaller R.sub.1 /R.sub.2 strain ratio for a given radius of curvature R.sub.2. For a cable of a given fiber count, ribbons having the smallest per each fiber count (smaller ribbon width) is the most desirable from a strain standpoint. However, from a fiber organizational standpoint, it would be more desirable to have as few ribbons as possible, i.e., wide width ribbons. Thus, the strain R.sub.1 /R.sub.2 and ribbon organization appear to be at odds with one another. It is to the solution of this problem that this invention is directed, wherein so called wide ribbons for organizational purposes can be used without increasing the R.sub.1 /R.sub.2 strain factor.